1. Field of the Invention
This invention relates generally to fluid flow valving devices. More specifically, the present invention relates to a valving device for a suction catheter system. Even more specifically, the present invention relates to a suction control valve useable with suction catheters attachable to a respirator manifold of a respiratory system.
2. Prior Art
Respiratory systems used for the ventilation of critically ill patients are now commonly used in medical facilities. Typically, a prior art respiratory system includes a tracheal tube positioned either directly or through the nose or mouth into the trachea of a patient, a manifold connected to the tracheal tube at one port position thereof, a source of breathable gas connected at a second port thereof, and a third port for allowing exhausted gas to exit the manifold. The purpose of the respiration system is to assist the patient in maintaining adequate blood oxygenation levels without overtaxing the patient's heart and lungs.
While a patient is attached to a respiration system, it is periodically necessary to remove fluid from the patient's trachea or lungs. In the past, it was necessary to disconnect the respirator system, either by removing the manifold or by opening a port thereof, and inserting a small diameter suction catheter down the tracheal tube and into the patient's trachea and lungs. The fluid was then suctioned from the patient and the suction catheter was removed and the respirator system reassembled. Because of the necessary interruption in respiratory support caused by this procedure, a patient's blood oxygen often dropped to an unacceptably low level during the suctioning, even when other previously known breathing assisting efforts were simultaneously provided.
A known solution to the above problem has been to place a fourth port on the aspirator manifold which is adapted to receive a connector of a suctioning device. A suctioning device such as used with this type of aspirator manifold is adapted to allow a suction catheter to remain permanently positioned within the manifold without the necessity of attachment or removal thereof from the manifold in between uses, thereby avoiding substantial manifold pressure loss. The suction device includes an envelope which is sealed around the suction catheter in order to prevent contamination of the suction catheter surface which is repeatedly inserted into and removed from the patient's trachea and lungs. This type of suctioning device allows continuous respiratory support of the patient during suctioning of fluid from the patient's trachea and lungs, and is commonly controlled by means of a valve located in fluid flow connection between the catheter and the suction source therefore. A valve of this type which is generally exemplary of the prior art is shown in U.S. Pat. No. 4,872,579. The valve selectively communicates vacuum pressure into the interior of a catheter tube when it is desired to evacuate respiratory fluids. The valve is normally biased to a closed position to prevent vacuum flow until a user initiated manual displacement of a valve actuator opens the catheter tube to the vacuum source. The valve actuator is also designed to be rotatable relative to the remain of the valve between an open position and a closed position in which actuation for suctioning is prevented.
There nevertheless remain several drawbacks associated with suction control valves of the prior art. For example, prior art suction control valves of the above described type fail to provide the user with an auditory indication of the continued availability of suction pressure for use. Further, when it becomes necessary to perform a suctioning procedure on the patient with other than the suction catheter to which the prior art valve is attached, as for example when a Yankauer device is required during a suctioning procedure in order to effect suctioning of the patient's mouth, it is necessary with the prior art suction control valves to disconnect the valve and suction catheter entirely from the suction source in order to replace them with the desired Yankauer device.